I stayed there for 10 days. I would say it's a small hotel rather than apartment. They have a front desk, cleaning services, key card, safe box, etc. It was nice, and I felt safe. The size of the room and the bathroom were quite good too. Good location to Silom road and the BTS stations (Chong Nonsi and Sala Daeng). I appreciate K's quick responses.
However, I had an inconvenient situation during my stay. Sometimes I encountered that they closed (locked) the entrance door when they were not at the front desk. I can understand it's for a security reason, but they shouldn't block the guests. I could't go out for about 5 minutes. Nobody came even I called several times, so I had to wait until someone came back.